Add all location permission related methods to view contract and implement in fragment. Call them from presenter by passing locationServiceManager parameter

app/src/main/java/fr/free/nrw/commons/nearby/mvp/contract/NearbyParentFragmentContract.java

@@ -1,10 +1,18 @@
 package fr.free.nrw.commons.nearby.mvp.contract;
 
+
+import fr.free.nrw.commons.location.LocationServiceManager;
+
 public interface NearbyParentFragmentContract {
 
     interface View {
         void setListFragmentExpanded();
         void refreshView();
+        void registerLocationUpdates(LocationServiceManager locationServiceManager);
+        void requestLocationPermissions(LocationServiceManager locationServiceManager);
+        void showLocationPermissionDeniedErrorDialog(LocationServiceManager locationServiceManager);
+        void checkGps(LocationServiceManager locationServiceManager);
+        void checkLocationPermission(LocationServiceManager locationServiceManager);
     }
 
     interface UserActions {

app/src/main/java/fr/free/nrw/commons/nearby/mvp/fragments/NearbyParentFragment.java

@@ -1,5 +1,7 @@
 package fr.free.nrw.commons.nearby.mvp.fragments;
 
+import android.content.Intent;
+import android.os.Build;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -14,10 +16,12 @@ import javax.inject.Inject;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.appcompat.app.AlertDialog;
 import androidx.constraintlayout.widget.ConstraintLayout;
 import butterknife.BindView;
 import butterknife.ButterKnife;
 import fr.free.nrw.commons.R;
+import fr.free.nrw.commons.contributions.MainActivity;
 import fr.free.nrw.commons.di.CommonsDaggerSupportFragment;
 import fr.free.nrw.commons.location.LatLng;
 import fr.free.nrw.commons.location.LocationServiceManager;
@@ -27,6 +31,7 @@ import fr.free.nrw.commons.nearby.NearbyListFragment;
 import fr.free.nrw.commons.nearby.NearbyMapFragment;
 import fr.free.nrw.commons.nearby.mvp.contract.NearbyParentFragmentContract;
 import fr.free.nrw.commons.wikidata.WikidataEditListener;
+import timber.log.Timber;
 
 /**
  * This fragment is under MainActivity at the came level with ContributionFragment and holds
@@ -50,8 +55,6 @@ public class NearbyParentFragment extends CommonsDaggerSupportFragment
     @BindView(R.id.loading_nearby_list)
     ConstraintLayout loading_nearby_layout;
 
-    @Inject
-    LocationServiceManager locationManager;
     @Inject
     NearbyController nearbyController;
     @Inject
@@ -138,4 +141,147 @@ public class NearbyParentFragment extends CommonsDaggerSupportFragment
     public void refreshView() {
 
     }
+
+    /**
+     * This method first checks if the location permissions has been granted and then register the
+     * location manager for updates.
+     * @param locationServiceManager passed from presenter to check updates if location
+     *                               permissions are given
+     */
+    @Override
+    public void registerLocationUpdates(LocationServiceManager locationServiceManager) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            if (locationServiceManager.isLocationPermissionGranted(requireContext())) {
+                locationServiceManager.registerLocationManager();
+            } else {
+                // Should we show an explanation?
+                if (locationServiceManager.isPermissionExplanationRequired(getActivity())) {
+                    new AlertDialog.Builder(getActivity())
+                            .setMessage(getString(R.string.location_permission_rationale_nearby))
+                            .setPositiveButton(android.R.string.ok, (dialog, which) -> {
+                                requestLocationPermissions(locationServiceManager);
+                                dialog.dismiss();
+                            })
+                            .setNegativeButton(android.R.string.cancel, (dialog, id) -> {
+                                showLocationPermissionDeniedErrorDialog(locationServiceManager);
+                                dialog.cancel();
+                            })
+                            .create()
+                            .show();
+
+                } else {
+                    // No explanation needed, we can request the permission.
+                    requestLocationPermissions(locationServiceManager);
+                }
+            }
+        } else {
+            locationServiceManager.registerLocationManager();
+        }
+    }
+
+    /**
+     * Request location permission if activity is not null
+     * @param locationServiceManager passed from presenter, to listen/un-listen location changes
+     */
+    @Override
+    public void requestLocationPermissions(LocationServiceManager locationServiceManager) {
+        if (!getActivity().isFinishing()) {
+            locationServiceManager.requestPermissions(getActivity());
+        }
+    }
+
+    /**
+     * Will warn user if location is denied
+     * @param locationServiceManager will be passed to checkGps if needs permission
+     */
+    @Override
+    public void showLocationPermissionDeniedErrorDialog(LocationServiceManager locationServiceManager) {
+        new AlertDialog.Builder(getActivity())
+                .setMessage(R.string.nearby_needs_permissions)
+                .setCancelable(false)
+                .setPositiveButton(R.string.give_permission, (dialog, which) -> {
+                    //will ask for the location permission again
+                    checkGps(locationServiceManager);
+                })
+                .setNegativeButton(R.string.cancel, (dialog, which) -> {
+                    //dismiss dialog and send user to contributions tab instead
+                    dialog.cancel();
+                    ((MainActivity)getActivity()).viewPager.setCurrentItem(((MainActivity)getActivity()).CONTRIBUTIONS_TAB_POSITION);
+                })
+                .create()
+                .show();
+
+    }
+
+    /**
+     * Checks device GPS permission first for all API levels
+     * @param locationServiceManager will be used to check if provider is enable
+     */
+    @Override
+    public void checkGps(LocationServiceManager locationServiceManager) {
+        Timber.d("checking GPS");
+        if (!locationServiceManager.isProviderEnabled()) {
+            Timber.d("GPS is not enabled");
+            new AlertDialog.Builder(getActivity())
+                    .setMessage(R.string.gps_disabled)
+                    .setCancelable(false)
+                    .setPositiveButton(R.string.enable_gps,
+                            (dialog, id) -> {
+                                Intent callGPSSettingIntent = new Intent(
+                                        android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS);
+                                Timber.d("Loaded settings page");
+                                startActivityForResult(callGPSSettingIntent, 1);
+                            })
+                    .setNegativeButton(R.string.menu_cancel_upload, (dialog, id) -> {
+                        showLocationPermissionDeniedErrorDialog();
+                        dialog.cancel();
+                    })
+                    .create()
+                    .show();
+        } else {
+            Timber.d("GPS is enabled");
+            checkLocationPermission();
+        }
+    }
+
+    /**
+     * This method ideally should be called from inside of CheckGPS method. If device GPS is enabled
+     * then we need to control app specific permissions for >=M devices. For other devices, enabled
+     * GPS is enough for nearby, so directly call refresh view.
+     * @param locationServiceManager will be used to detect if location permission is granted or not
+     */
+    @Override
+    public void checkLocationPermission(LocationServiceManager locationServiceManager) {
+        Timber.d("Checking location permission");
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            if (locationServiceManager.isLocationPermissionGranted(requireContext())) {
+                refreshView(LOCATION_SIGNIFICANTLY_CHANGED);
+            } else {
+                // Should we show an explanation?
+                if (locationServiceManager.isPermissionExplanationRequired(getActivity())) {
+                    // Show an explanation to the user *asynchronously* -- don't block
+                    // this thread waiting for the user's response! After the user
+                    // sees the explanation, try again to request the permission.
+                    new AlertDialog.Builder(getActivity())
+                            .setMessage(getString(R.string.location_permission_rationale_nearby))
+                            .setPositiveButton(android.R.string.ok, (dialog, which) -> {
+                                requestLocationPermissions();
+                                dialog.dismiss();
+                            })
+                            .setNegativeButton(android.R.string.cancel, (dialog, id) -> {
+                                showLocationPermissionDeniedErrorDialog();
+                                dialog.cancel();
+                            })
+                            .create()
+                            .show();
+
+                } else {
+                    // No explanation needed, we can request the permission.
+                    requestLocationPermissions(locationServiceManager);
+                }
+            }
+        } else {
+            refreshView(LOCATION_SIGNIFICANTLY_CHANGED);
+        }
+    }
 }

app/src/main/java/fr/free/nrw/commons/nearby/mvp/presenter/NearbyParentFragmentPresenter.java

@@ -1,6 +1,9 @@
 package fr.free.nrw.commons.nearby.mvp.presenter;
 
+import javax.inject.Inject;
+
 import fr.free.nrw.commons.location.LatLng;
+import fr.free.nrw.commons.location.LocationServiceManager;
 import fr.free.nrw.commons.location.LocationUpdateListener;
 import fr.free.nrw.commons.nearby.mvp.contract.NearbyParentFragmentContract;
 import fr.free.nrw.commons.wikidata.WikidataEditListener;
@@ -9,6 +12,9 @@ public class NearbyParentFragmentPresenter
         implements NearbyParentFragmentContract.UserActions,
                     WikidataEditListener.WikidataP18EditListener,
                     LocationUpdateListener {
+    @Inject
+    LocationServiceManager locationManager;
+
     private NearbyParentFragmentContract.View nearbyParentFragmentView;
 
     public NearbyParentFragmentPresenter(NearbyParentFragmentContract.View nearbyParentFragmentView) {
@@ -25,8 +31,15 @@ public class NearbyParentFragmentPresenter
         initializeNearbyOperations();
     }
 
+    /**
+     * Initializes nearby operations by following these steps:
+     * - Add this location listener to location manager
+     */
     @Override
     public void initializeNearbyOperations() {
+        locationManager.addLocationListener(this);
+        nearbyParentFragmentView.registerLocationUpdates(locationManager);
+
 
     }